Question

why trekkers and mountaineers usually carry chlorine tablets with them?

Answer 1

Mountaineers or trekkers usually suffer from nose bleeding at higher altitude because as we go up the atmospheric pressure decreases . on the place where we live the atmospheric is balanced as the pressure Inside our body cancels the atmospheric pressure outside. so due to decrease in atmospheric pressure the mountaineers suffer nose bleeding
So in ordet to avoide bleeding they carry chlorine tablets.